Estimate bolt speed, kinetic energy, and gravity-based drop from your crossbow's published speed and your bolt weight. Includes a reference drop chart by distance.
Enter your crossbow's advertised speed and your actual bolt weight to get realistic FPS, KE, and drop.
Speed = Published × √(RefWeight ÷ YourWeight) × Efficiency
KE = (grains × fps²) ÷ 450240
Drop = ½ × g × (distance ÷ speed)²
Approximate drop from a 20-yard zero at various bolt speeds. Real drop varies with bolt BC, fletching drag, wind, and crossbow tune.
| Distance | 300 fps | 350 fps | 400 fps | 450 fps |
|---|---|---|---|---|
| 20 yd (zero) | 0.0" | 0.0" | 0.0" | 0.0" |
| 30 yd | 5.4" | 3.9" | 3.0" | 2.4" |
| 40 yd | 13.5" | 9.8" | 7.5" | 5.9" |
| 50 yd | 25.0" | 18.2" | 13.9" | 11.0" |
| 60 yd | 41.0" | 29.8" | 22.8" | 18.0" |
| 80 yd | 86.9" | 63.2" | 48.3" | 38.2" |
| 100 yd | 155.0" | 112.6" | 86.2" | 68.1" |
Values are pure gravity drop from a 20-yard zero — no drag. Real-world drop will be slightly higher at longer distances. Use these as a starting point, then confirm with your scope's ballistic reticle or by shooting at distance.
The FPS and KE estimates are typically within 2–4% of a chronograph reading for the same bolt. Drop estimates are pure gravity models — real drop is usually 10–20% higher at long distances due to aerodynamic drag.
Manufacturers test with a light bolt under ideal conditions. Heavier hunting bolts, string silencers, and rail accessories all add drag and reduce real speed. Real hunting setups typically run 15–35 fps slower than the box claim.
Most crossbow hunters shoot 400–500 grain bolts, including a 100–125 gr broadhead. Heavier bolts offer better penetration but require more drop compensation. Verify your crossbow's minimum bolt weight before buying.
Yes. Enter the published speed for your specific crossbow. A 150 lb crossbow typically publishes 280–320 fps; a 175 lb typically publishes 320–360 fps.
Yes — the drop model is the same. For bow-specific drop analysis, use our arrow drop calculator.